Jonas kendall



@uiten tatrsl getint @ffice JONAS KENDADL, OF SOUTH FRAMINGHAM, AND ADDISON HATHAWAY, OF LENOX, ASSIGNORS. TO ANDREW T. SERVEN, OF LENOX, MASSACHUSETTS# Letters Patent No. 79,131, datecZ-June 23, 1868.

IMPROVBD MAGHNE FOR GRINDING GLASS PLATS, dto.

TO ALL WHOM vIT MAY CONCERNE Be it known that we, Jonas KuNpALL, o'f South Framingham, Middlesex county, and ADDIsoN'HArHAWAY, of Lenox, Berkshire county, all in the State of Massachusetts, have invented an Improvement in Machines for `Grinding Glass Plates, &c.; and we do hereby declare that the following, taken in connection with the drawings which accompany and form part of this specification, is a description of our invention suiicient to enable those skilled in 4the art to practise it. l Y

Our invention relates particularly to an organization of mechanism for grinding orA reducing the surfaces of glass plates, the invention being particularly designed for bringing the surfaces' of such plates to perfectly uniform planes.

In carrying out our invention, we employ a reciprocating carriage or table for holding the plate to be ground, i

and a series of circular-grinding-disks, the disks having a rotary motion about a central common axis; and our invention consists, primarily, in imparting to each of these grinding-disks a positive rotary motion on its own axis.

The drawings represent amachine embodying our improvements.f l

A shows the same in end elevation. i

B is a side elevation thereof.

C, a plan.

a denotes a frame, having ways, b, upon which 'is mounted a sliding carriage, c, the upper surface of which forms the table upon which the plate of glass to be worked is placed'and confined for the action of the grindingmechanism. i

This carriage hasl a gear-rack, into which meshes a gear' on a shaft, d, rotation of the shaftlin alternate directions effecting reciprocating horizontal movements of the carriage. l

Over the table c, between uprights e, is a frame, f, having bearings,'in which is mounted 'a vertical shaft, la). On the lower end of this shaft is fixed a wheel, t', carrying a series of grinding-disks or tools, k, eachsupported on the lower end of a vertical shaft, Z, rotating 'in a bearing on the wheel a'.

The wheels' has a rotary motion imparted to it" through the shaft t, (by means of a gear, riz, on a shaft, n, meshing into and driving a gear, o, onl the shaft h, or in any other suitable manner,) and this rotary motion of the wheel,l as will be readily seen, gives a movement to each grinding-disk across the face of the reciprocating plate, traversing to and fro beneath the grinders, with and upon the reciprocating table.

We have found'in practice, however, that thel rotary motion imparted to each disk by friction, under the compound traversing motion of the plate and rotary motion-ofA the wheel, is unreliable, in that, under slight obstructions, the disks 'remain stationary relatively to the wheel', and `that the plate is thus prevented from being uniformly reduced, scratches being also often made `uponithe surface being ground. These difficulties we ind we can overcome by giving to each disk, as it revolves around the axis 7i, a positive rotary motion on its own` axis, 4and to effect this we x on the top ofeach shaft Za gear-pinion,p,the several pinionsp meshing into the teeth ofa stationary gear, q, fixed to the frame f, the rotation of the pinions around this gear effecting the rotation of each on its own axis, and the consequent rotation of the grinding-disk on its axis.

It will be obrious that this will overcome any tendency of any disk to scratch or to work irregularly on the surface of. the plate beneath it.

Where 'the motion of the disks isnot thus made positive, each disk is apt to get sprung from its horizontality, as it passes upon and olf from the end of a plate, and if 'this -horizontality is not kept up, the disk will soonrnaintainl a ixed position'relativeiy to the wheel, or will fait to-be rotated by friction against the plate, and will consequently fail t9 grind the glass surface down to aperfect plane.

Gearing the grinding-disks, as shown, causes every part of the disk to act uniformly, the surface of the glass being subjectedl to the vcompound motion of the table on its ways, the motion of each disk across its surface, and the motion of each disk on its' axis, and plates thusA ground are found to present fewer defects than those'groundin any other manner.

The opposite ends ofthe framef are sustained in grooves in the uprights e,aand the frame is made capable of vertical movement in these grooves, to feed the grinding-disks down as they reduce or wear away the surface of the glass. i

The frame is hung on screws, r, working in threads in the top rail s of `the frame, the serew-shafs being mounted in a cross-piece, t, and bearing, at their upper ends, bevelgears u, driven by pinions v on a cross-shaft, un

To impart an automatic downward movement to the grinders, at the end of each movement of the carriage c, and in connection with the shipping-mechanism for effecting alternate movements of the carriage, by changing the direction of motion ofthe shaft at the end of each forward or back movement of the carriage, a mechanism is employed, as follows:

The shaft w has at at one end a gear, x, 'which meshesinto and is driven by a gear, y, on top of a shaft, z, the lower end of shaft e having a gear, a, driven by a gearz, en a shaft, c2. Shaft c2 carries a ratchebwheel, d2, into the teeth of' which engages a pawl, e2. This pawl is connected to and is actuated by a lever, f2, hung on a.- fuleram, g2, and havingian arm, h2, extending in towards the carriage e, as shown at A and C. On the edge of the carriage c, in line with this arm, are two inclines, z'z, and as the movement of the carriage in either direction is terminating,7 one ofthese inclines passes under the arm h2, and, by 1'aisin'g'it,depresses the opposite end o f the lever, thereby forcing down the paavl e2,"(which is held against the ratchet by a suitable spring,) and turning the ratchet, the movement of the ratchet communicating motion (th-rough the train of gearing just described) tothe frame f, and thereby gradually letting down the grinding-disks as' the reduction of the surface of the plate progresses. The ratchet-pawl is returned to its normal position, after the incline passes from it, by a suitable'spring, r.

'The shaft e carries a hand-wheel, j, by rotation of whichthe grinders may be raised and lowered in introducing the glass and setting the machine to work, ori-n removing the glass. K i

Adjacent to-each incline i2 is a dog, 7a2, which, as the carriage is completing its movement, strikes an arm,

J2, o.r a lever m2 the o osite end of which is 'ointed to an arm n.2 of a shi er-fork o2, thelmovement of the t r a PP .l v v PP i lever m2, in either direction, by either dog, k, shifting the-belts, and thereby changing the direction of motion'y of the carriage, this change taking place simultaneously with or immediately subsequent to the downward movement of the grinding-disks, as above described.

We claim, in combination `with the series of diskstor grinders, rotating around a common axis an'dl overl a reciprocating table, giving to each disk or grinder a. positive rotary motion on itsown axis, substantially-as described.'

lWe also claim', in combination with the rotary grinding-disks, the mechanism for automatically effecting their downward movement as the grinding progresses, substantiallyras described.

JONAS KENDALL, lADDISON HATHAWAY.

Witnesses:

Fnmcrs Gouw, i

C. WARREN Bnown.l 

